[pbs-devel] [PATCH proxmox v3] router: cli: added `ask_for_confirmation` helper

[Fabian Grünbichler]

On September 27, 2023 12:13 pm, Wolfgang Bumiller wrote:
> On Fri, Sep 08, 2023 at 01:44:09PM +0200, Gabriel Goller wrote:
>> Added `ask_for_confirmation` helper that outputs a prompt and
>> lets the user confirm or deny it. Also added localization using
>> `libc::nl_langinfo()` to match/show a `yes` or `no` in the correct
>> language.
>> Implemented to close #4763.
>> 
>> Signed-off-by: Gabriel Goller <g.goller at proxmox.com>
>> ---
>> 
>> update v3:
>>  - added localization using `libc::nl_langinfo`
>> 
>> note: skipped to version 3, so that the whole patch series has 
>>       the same version number.
>> 
> [..]
>> +    use std::ffi::CStr;
>> +    let yes_expr = unsafe { CStr::from_ptr(libc::nl_langinfo(libc::YESEXPR)) }
>> +        .to_str()
>> +        .unwrap_or("^[yY]$");
>> +    let no_expr = unsafe { CStr::from_ptr(libc::nl_langinfo(libc::NOEXPR)) }
>> +        .to_str()
>> +        .unwrap_or("^[nN]$");
>> +
>> +    let n = no_expr.chars().find(|c| c.is_uppercase()).unwrap_or('N');
>> +    let y = yes_expr.chars().find(|c| c.is_uppercase()).unwrap_or('Y');
>> +    print!("{query} [{y}/{n}]: ");
> 
> Usually, the uppercase letter is used for the default for when typing
> nothing, while the other one is lowercase.
> 
> Now I was also wondering what we should do if no upper/lowercase letter
> exists, but then again, it seems yY and nN are pretty much always
> included. I checked at least de_DE, ja_JP and zh_CN next to en_US, and
> I'm fairly certain we can rely on that, since I'm assuming this is
> exactly what `rpmatch(3)` does, which explicitly states that `y` and `n`
> work regardless of locale.

there definitely are locales that either don't include 'y' and/or 'n',
or do so in a misleading manner.

one example:

$ LC_MESSAGES=sw_KE.UTF-8 locale yesexpr
^[+1nNyY]

$ LC_MESSAGES=sw_KE.UTF-8 locale noexpr
^[-0hHlL]

this is also the case for nl_langinfo, at least if the code in question
actually calls setlocale/uselocale at some point, which we don't do I
think?

in any case, I am not sure whether localizing just the prompt answers
makes much sense, if we don't localize log messages/CLI output/.. in
general?